Sorry you had that kind of trouble. The worst I've found is the mulch isn't always shredded well. I can see where the extra added "materials" might be offputting.
Sounds like Andy is a real help. Are his kids old enough to be taught the difference between weeds and plants? Can they be bribed with cookies or something?
Maybe we should get a group of people together to make roving visits to each other's houses. Kind of like a neighborhood pot luck where everyone brings a different dish. Only here, they bring bags of mulch, pots, and labor to spread the mulches, tidy up, lay pavers, move plants, and stuff. Start regional and grow to national club status.